| 摘要 |
<P>PROBLEM TO BE SOLVED: To effectively suppress evaporative wear of electrode members under increased temperature when lighting a DC lighting type of high pressure discharge lamp. <P>SOLUTION: A DC lamp lighting device (1) includes a PWM control circuit (21) for performing constant power control to maintain a lamp power calculated from a lamp current and a lamp voltage at a preset rated power. The control circuit (21) includes: current priority control means (23) for maintaining the lamp current at a constant target current value set lower than a rated current; power priority control means (24) for compensating for a power drop resulting from the current reduction by the current priority control means (23) to maintain an average power at the rated power; and timing control means (25) for alternately switching between the control means at a preset control period on the order of milliseconds. <P>COPYRIGHT: (C)2012,JPO&INPIT |
